As is known in the art, radar systems have been developed for various applications associated with vehicles, such as automobiles and boats. A radar system mounted on a vehicle detects the presence of objects including other vehicles in proximity to the vehicle. In an automotive application, such a radar system can be used in conjunction with the braking system to provide active collision avoidance or in conjunction with the automobile cruise control system to provide intelligent speed and traffic spacing control. In a further automotive application, the radar system provides a passive indication of obstacles to the driver on a display.
A continuing safety concern in the operation of automobiles is the difficulty in seeing objects in the side blind spots of the automobile. Accidents often occur when an automobile impacts another vehicle in its blind spot when changing lanes.
Rear and side view mirrors of various sizes and features are typically used in an effort to improve visualization of blind spots. For example, convex mirrors provide a larger view than flat mirrors. However, objects viewed in a convex mirror appear farther away than their actual distance from the vehicle. Also, the view through mirrors degrades during conditions of rain, snow, or darkness.
There is a need for an effective way to detect obstacles in a vehicle's blind spots, and generally in close proximity to the vehicle, which is accurate and reliable during all types of environmental conditions including rain, snow, and darkness. A further characteristic of an effective detection system is a well-defined detection zone within which there is a very high probability of detection, and outside of which there is a very low probability of detection.